Why Neville Hates Baker Street
by Robina Snyder
Summary: Neville Longbottom is dropping of a house warming gift for a former student and ends up meeting the world's only consulting detecive. Short crossover between Sherlock and "The Lestrange Child"


A/N: This in no way relates to the actual story. I've been currently obsessed with Harry Potter/Sherlock crossovers. I don't know Sherlock well enough to write him his own story, so I just tacked him onto one of the stories I was already working on. This in no way relates to the actual plot or character progression of _The Lestrange Child. _This is mostly practice for me writing Sherlock and older!Tacita.

Some context, this is after "The Reichenbach Fall", set in 2015. Tacita graduates from Hogwarts in 2014. John's married already and comes by and visits sometimes. Sherlock's been back for a while. Professor Bentley is a character in _The Lestrange Child_ that simply hasn't shown up yet. This is merely for my own fun.

* * *

Neville Longbottom wished he didn't know why he was dropping off a plant (a peace lily, perfectly sensible for someone living in Muggle London, also nearly impossible to kill given that it's watered every so often and not thrown off a roof) to one of his former students. Sadly he knew exactly why. His wife had sent him out the door, plant in hand, only about an hour before. He would have arrived at Baker Street sooner if he hadn't decided to pretend he didn't know exactly how to use the tube system and hadn't pretended to miss his stop and get off two stops later, only to wish that he'd gotten off on the right stop, which would have meant a bit less walking, giant plant in hand.

He didn't even need to play back the conversation that had gotten him out of the door. _"She's your former student and she lives incredibly close and she always spends a good bit at out pub. Be a good man and drop off a housewarming gift._" Really, all Hannah would have had to do was tell him to go and he'd have gone, but he sensible words would probably make him stick around for a cup of tea if it was offered. Why did he have to do this alone? _"I told you, dear, someone has to stay and tend the pub."_ Oh yeah, that's why.

Neville sighed as he passed Speedy's Sandwich Bar & Café, glancing wistfully at the store and wishing he could avoid is mission for a few more minutes with a bowl of stew. He decided against it and instead propped his foot of the front step of 221b Baker Street, balancing his plant on said knee in order to have a hand to knock on the door.

"Oh, hello dear, are you hear to see Sherlock?" a proper older middle aged woman (who reminded Neville of a thinner, blonde Mrs. Weasley) asked as she answered the door.

" 'Fraid not, ma'am," Neville, shifting for more natural position, wrapping both his arms around the wicker pot covering. He didn't even know who 'Sherlock' was, but he just wished that he had reason to see him and not the person he'd actually come to call on. "I'm here to see Tacita Lestrange, I'm an old professor… she does live here, right?" he asked, suddenly struck with the sudden panic that he'd gotten the wrong address and would be stuck eternally wandering the streets of London with the infernal plant (he certainly couldn't come home with it).

"Oh, then do come in please," she said, letting him in before shutting the door. She maneuvered around him in the skinny hallway and led her up the stairs. "She lives in 221c, but I'm afraid the kitchen doesn't work very well there, and Sherlock doesn't seem to remember to cook for himself," she said, sounding both worried and sympathetic, as she knocked on the door to 221b. "Tacita, there's someone here for you," she called, stepping in, letting Neville in.

The room was messy, books everywhere, a skull on the mantel place, and so many beakers and test tubes that Neville had to wonder if Horace actually had let their formal pupil raid his supplies before she graduated. Then he caught sight of the man. He was sprawled out in a chair, his over long legs taking up more space than was proper when sitting in a chair. He gave Neville a cold look under his mop of brown curls before going back to looking at the ceiling.

"Is it Granville? Can't we just give me a key? He show up enough on his own as it is," Tacita said with exasperation, coming out of the kitchen. The first thing Neville Longbottom noticed (warily) was the rather large knife in the 18 year old's hands. The second thing he noticed was that every single finger but one had a bandage on it, and the one that didn't was bleeding profusely.

"Oh dear, you cut yourself again," the woman said, bustling past Tacita Lestrange, taking the knife as she went.

"I don't know Mrs. Hudson, I don't think I'm cut out for this house wife business," the young woman said, smiling at the woman who just gave her a look and went back to finding the first aid kit. It was then that Neville's former pupil actually noticed him. "Hello professor," she said, her voice getting much softer and much more unsure. She seemed tired.

"Ms. Lestrange," Neville responded, being sure to pronounce her name right. "My wife sends her regards and this plant," he said.

"Spathiphyllum cochlearispathum, boring," the man said from his position still sprawled across both chair and floor.

"A Peace Lily, perfect," Tacita said. "Thank you Mrs. Hudson," she said, letting the woman tend to her bleeding hand. "You can just set it down somewhere. It can't make this place any more cluttered."

"Do you plan to leave it here?" Neville asked, eyeing the room.

"No, Sherlock will probably uproot it and use it for an experiment," Tacita said with a heavy sigh, turning her head to look at the man in the chair. Neville could imagine the look, annoyed, cold, just like her mother. He didn't even see it, but he still shivered. He noticed then that the man was looking at him.

"Ignore him. He's part of the furniture," Tacita said, drawing Neville's attention back to her. "Thank you Mrs. Hudson," she added as the woman finished bandaging her finger.

"That isn't very nice, dear," Mrs. Hudson chastised.

"Shut up Mrs. Hudson," the man in the chair said, suddenly standing up. Neville noticed that her was wearing a shirt about a size and a half too small for him, and a dark blue dressing gown that billowed out behind him in a manner more reminiscent of Snape than Neville thought anyone should have. "Tea," the man added.

"I'm not your cleaning lady, dear," Mrs. Hudson said, but proceeded to go make tea anyway.

Neville ignored them, focusing on his ex-student and her hurt fingers. "What happened?"

"I'm a terrible cook," Tacita said simply.

"Really? I've heard cooking is just like P-"

"Chemistry, yes I know," Tacita said, her eyes darting to the man in the blue dressing gown he was perusing his overstuffed bookshelf. "Professor Bentley said the same thing, got me a book on the science of cooking. It hasn't made me any better at it," she said.

An awkward silence stretched out, broken only by the sounds of Mrs. Hudson making tea in the kitchen. Finally Neville spoke, not sure what else to do. He knew from experience that Tacita Lestrange would let and uncomfortable silence stretch on for eternity.

"Mr. Jorkins is around often?" he asked.

"Yes, they both are," Tacita said.

"Ah, Grimwold Jorkins is around often, is he?" Neville said, just grasping at straws. "I thought he was playing some sport… what was it again?"

"Rugby," Tacita lied smoothly. They both knew he was playing for the Chudley Cannons. Ron Weasley loved him.

"Wrong," the man said from where he was perusing some book.

"Sherlock," Tacita said, turning a little too slow to look at him. "You know most men at your age would spend their off hours looking at internet pornography. Can't you take up a nice hobby like that?" she asked. Neville proceeded to choke on nothing. "Instead of annoying people who come to cook for you."

"I'd hardly call what you 'cook' food. I'm not even sure I'd call most of it edible," the man said, his eyes still running over the book like he was reading it.

"Then you must not be human, because I'd seen you eat enough of it," she said. "You don't even complain about my biscuits."

"Your biscuits are acceptable," the man said. "The same cannot be said for the stew you keep attempting to make."

Tacita shrugged. "I am aware," she said before turning back to her old professor. She said nothing though, not really wanting to engage with the man.

"Tea's ready," Mrs. Hudson said, bustling out with a tray, three cups of tea prepared, though the third, completely black, was clearly meant for Neville to doctor as he saw fit. "Here you go dear," she said, setting down the tray on the coffee table nearest the sofa. Neville took it as a cue to sit down there and did so, leaving the plant nearby once he'd sat. "You know, I didn't get your name, dear," the older woman said.

"Neville, Neville Longbottom, ma'am," he said politely.

"Oh please," the man in the blue dressing gown said, accepting the cup of tea Mrs. Hudson handed him without a word of thanks.

"Excuse me?" Neville asked.

"Professor, please don't," Tacita said, taking her tea. "Just treat him like furniture. Ignore him, he just wants to show off," she said, taking a long sip of tea.

"I take it this one is related to one of your mother's victims? Someone close, a parent most likely," the man said, sipping his tea.

"How?" Neville asked, but Tacita shook his head. She kept her back firmly to Sherlock.

"Don't encourage him. First day I got here he told me that my parents were serial killers, and he's been trying to figure out who ever since. I think it's starting to drive him right batty," she said. She turned her head to look at Sherlock, smirking at him for a moment before she turned back to her old professor. Neville caught sight of it and shivered for just a moment. He didn't hate the girl anymore, but she never made him comfortable.

"Your parents died when you were young," Sherlock said. "Most likely raised a close relative, and aunt or grandmother, definitely maternal and strict. You struggled with classes and attached yourself to the one thing you were good at, good enough to be a professor at a young age. Talent combined with hard work that isn't common unless a student has a reason: either parental pressure or a lack of social connections. You've also worked with the police in the past, retired now, but your stance still gives you away. Married, twelve years, two children."

Neville looked at the man, who'd gone back to sipping his tea, like he'd grown a second head.

"Ignore him, he just wants attention," Tacita said, finishing her tea. Neville took her words under advisement.

"How is your studying?" he asked. The man gave him an annoyed look that was quickly masked by boredom as he went back to his book shelf.

"Boring, but the tests are in a few months," Tacita said.

"You're sure about this?" Neville asked.

"Professor Bentley had been helping men," she said.

"Puh, that fraud, never graduated from and accredited institution," the man said.

"And you've gone to school to be a consulting detective?" Tacita asked.

"Well," Neville said, finishing draining his tea enough to nearly scald his tongue. "This has been enlightening, but I need to head home. Do take care," he said.

"Of course," Tacita said.

"Oh dear, you're not staying?" Mrs. Hudson asked.

"No, I'm afraid I need to get home to my wife," Neville said.

"You're trying to escape from a situation you're uncomfortable with, between the daughter of a serial killer and the world's only consulting detective you've decided it's better to burn your tongue and get out than stay."

"That too," Neville said. "Enjoy your plant. Hannah hopes you'll come visit soon," he said.

"I'll stop by," Tacita said vaguely waving goodbye to her old professor as he walked off. "You become quiet adolescent when you haven't seen John in a week," she said to Sherlock, making him glare at her. She ignored the look, going back to the kitchen. "I know I'm a poor substitute, but he's on his anniversary, and you were dead for three years."

"I am going to find out who she is," Sherlock said, going back to sprawling in his chair. "And you're going to cut yourself three more times before you finish the stew, which will be hardly edible."

"And you'll eat it anyway because you'll get fussed at later if you don't," she said, ignoring his other words. Secretly she knew he would find out… but she wasn't sure what she was going to do when he did. He just annoyed her too much to simply move out.


End file.
